Zacharias the Everliving is a Necrach Vampire riding a Zombie Dragon. He is in possession of an original copies of one of the Nine Books of Nagash, containing the knowledge of Nagash, the Great Necromancer. He rules the Forest of Shadows.
Zacharias studied Necromancy under the supervision of Dieter Helsnicht. Little is known of what he was before, but one day he discovered the location of Melkhior's hidden tower which lay in the Forest of Shadows in the Empire. Melkhior had stolen the Book of Nagash from Wsoran who had been given the book from Nagash himself. Zacharias set off and snuck into the tower in an attempt to steal the book, but was caught by Melkhior's Undead minions. Instead of killing the thief, Melkhior turned Zacharias in a Vampire and taught him the dark arts for many years.
Zacharias first damned his master for making him a vampire, but he soon complied and was a good and quick student. However, the Book of Nagash was kept far away from his curious eyes and one day, when Melkhior was indulging in the blood of his freshly killed servants, Zacharias descended to the tower's crypt and picked up the unholy tome. Unfortunately, Melkhior caught him and the two fought. Zacharias escaped with his un-life and fled to hide in the Middle Mountains east of Middenheim where he frequently had to move to escape the minions of Melkhior who where searching for him. At last finding a safe hiding place, he fell into a slumber for a decade.
When he woke, he discovered that he had gained company in his cave: a Black Dragon had chosen the exact same place to rest, unaware of the Vampire's presence. Zacharias drank deeply from the Dragon's blood and survived a month on the beast, gaining untold strength from it. It is said that drinking the blood of a dragon frees the vampire from its need for blood. After the dragon was empty, Zacharias raised the dragon from death and flew back to Melkhior to extract his revenge. Melkhior was driven out, or killed, no-one knows, and Zacharias, attaining the Book of Nagash and all the other wealth Melkhior had gathered, took residence in the Necrach's tower. He there rules the Forest of Shadows, men and Orc fearing him alike.